Police say they believe missing Iowa cousins were abducted

(Reuters) - Authorities in Iowa searching for two young cousins who disappeared last week said on Friday they were now treating the case as an abduction after an FBI dive team determined the girls' remains were not in a lake near where they were last seen.

Elizabeth Collins, 8, and Lyric Cook, 10, disappeared around noon last Friday shortly after they left their grandmother's house near Evansdale in northeast Iowa.

Their bikes and a purse were found near Lake Meyer, prompting investigators to drag it over the weekend and to begin draining it earlier this week.

The decision to suspend the search of the lake and to reclassify the case as an abduction came after divers using sophisticated sonar searched the body of water and concluded the girls were not in it.

Rick Abben, chief deputy with the Black Hawk County Sheriff's office, said investigators still had no single person of interest in the case. "Now that it's an abduction, everyone's a suspect," he said.

Abben said investigators had recovered some evidence and sent it to the Iowa Division of Criminal Investigation for analysis. He declined to say what the evidence was or where it was found.

Abben also confirmed that investigators had asked a judge to compel Lyric's father, 36-year-old Daniel Morrissey, who faces drug charges but is free on bond, to submit to closer watch by parole officers pending his trial.

He said the request -- which was granted on Thursday -- did not imply that Morrissey, who has stopped cooperating with investigators, was a suspect in the case.

"That was done so that we have a little bit closer ... supervision of people," Abben said. "We are not looking at anyone. Everyone is being checked into."